1. Field of the Invention
The present invention relates to a liquid crystal display device and, more particularly, to a liquid crystal display device which aims at the low power consumption.
2. Description of the Related Art
A TFT (Thin Film Transistor) type liquid crystal display module has been popularly used as a display device of a portable equipment such as a notebook type personal computer or the like. Particularly, the liquid crystal display module which is provided with a miniaturized liquid crystal display panel is used as a display device of a portable equipment such as a mobile phone, for example, which a user always carries.
The portable equipment is required to be operated for a long time by battery driving. Accordingly, the liquid crystal display module which is served for such an application is requested to satisfy the low power consumption.
On the other hand, when the same voltage (DC voltage) is applied to a liquid crystal layer for a long time, a display quality is deteriorated including the occurrence of an image retention phenomenon.
To prevent the deterioration of the image quality, in the liquid crystal display module, the voltage applied to the liquid crystal layer is alternated for every given fixed time. That is, using a voltage applied to a common electrode as the reference, a voltage applied to pixel electrodes is changed to a positive voltage side/a negative voltage side for every fixed time.
As a driving method which applies the AC voltage to the liquid crystal layer, there has been known a common inversion method which alternately inverts the voltage applied to the common electrode and the voltage applied to the pixel electrodes to the positive voltage side and the negative voltage side.
Further, with respect to the liquid crystal display module which is driven by the common inversion method, there has been known a liquid crystal display module which recovers a charge stored in a liquid crystal display panel so as to achieve the low power consumption (International Publication Pamphlet WO96/37803, Japanese Unexamined Patent Publication Hei10 (1998)-293559).